ETH Zurich : Computer Science : Pervasive Computing : Distributed Systems : Education : Student Projects : Abstract

Twitter for real-world objects (M)

Status: Abgeschlossen

About the Web of Things

This project is a core contribution our on-going the development of the Web of Things (WoT). WoT is a vision for the Web of tomorrow. As more and more embedded devices (consumer electronics, mobile phones, machines, energy meters, RFID tags, etc) can be connected to the Web, we propose to adapt and extend the principles behind Web 2.0 (sharing, online communities, interactive Web applications, semantic Web, APIs, etc) and extend them for physical devices as well. Imagine a world where everything around you has an URL and is a Web server that can be accessed directly with your browser or favorite HTTP client. Now think about creating Web mashups that combine any web content with physical objects around you into high level Web application that can react and use real-time data from the physical world. Think of your cat and iphone twittering their location directly into google maps. Imagine a Web page where you can entirely control your house or garden. Think of the endless possibilities of integrating the physical world as part of the internet, and allowing access to your devices only to your closest friends on facebook. That is what the Web of Things is all about.

Web messaging

More and more devices can connect to the Web and can be accessed directly using HTTP, just like any other Web content. Unfortunately, HTTP was mainly designed as a request/response protocol. For most application such as environmental or facilities monitoring, especially for security applications where notifications about events must be propagated as soon as possible, the classical pull-based, client-server model of HTTP is not appropriate. As such we propose to investigate a scalable solution for Web-based messaging which is particularly appropriate for embedded devices. Besides, a new type of web-based push messaging is becoming popular in the Web community (Web-hooks and Comet), as proved by the recent Opera browser and Web sockets in HTML5 specification. Web-based messaging is a very hot topic nowadays, as more and more companies realize the potential for web-based push publish/subscribe systems, and many startups and open source projects are going in that direction (lightstreamer, APE), however, projects that particularly focus on the requirements for embedded devices are yet missing.

Project goal

The first step of this project is to investigate the available messaging systems and compare their strength and weaknesses, particularly in regard to embedded devices. Then, publish-subscribe mechanisms (especially web-based ones, such as RSS, ATOM, XMPP, etc) should be thoroughly analyzed and evaluated in terms of performance and ease of use. Based on this initial survey, a lightweight messaging system will be designed for embedded systems that are fully web-compliant and that support all the messaging patterns that are required by enterprise systems (request/response, streaming, eventing).

If time allows, a topic-based publish/subscribe will be evaluated (smart mailing list based on keywords), where dynamic topic queues on the gateways will offer queues that notifies all the observers based on their interests (XMPP, protocol buffers, XML, binary XML, OSC). For example, one could specify that energy consumption data is pushed to the city's energy provider, fire alerts are pushed to fire services of the city, and security-related events will be send to the police services.

The outcome will be a Web-based notification mechanism both suited for devices and applications that will allow to blend easily the Web with the physical world. A prototype system will be implemented directly on embedded devices (Sun SPOTs or TMotes), and will be thoroughly evaluated in comparison with existing approaches. A Web-based demonstrator will illustrate the benefits of using full web-enabled messaging at the devices layer, and how easily it can integrate into other Web applications. According to the final result, different outcomes can be considered, such as a patent, publications and/or IETF/W3C draft for becoming a Web standard.

References:

[1] Guinard, Dominique, and Vlad Trifa. "Towards the Web of Things: Web Mashups for Embedded Devices." In Workshop on Mashups, Enterprise Mashups and Lightweight Composition on the Web (MEM 2009), in proceedings of WWW (International World Wide Web Conferences). Madrid, Spain, 2009.

[2] Erik Wilde. "Putting Things to REST", UCB iSchool Report 2007-015, School of Information, UC Berkeley, 2007.